1. Field Of The Invention
This invention relates to a new and useful improvement in synthesizing crystalline silicate having the structure of ZSM-11, and the new ZSM-11 synthesized .
More particularly, this invention relates to an improved method for preparing crystalline silicate ZSM-11 whereby synthesis is facilitated and reproducible and the silicate product high purity and catalytic utility.
2. Discussion Of Prior Art
Crystalline silicate ZSM-11 and its conventional preparation, e.g. from a reaction mixture containing a quaternary compound directing agent, such as a tetrabutylammonium compound, are taught by U.S. Pat. No. 3,709,979, the entire disclosure of which is incorporated herein by reference. It has a distinctive X-ray diffraction pattern which identifies it from other known crystalline silicates. Synthesis of crystalline silicate ZSM-11 from a reaction mixture containing C.sub.7 -C.sub.12 alkylenediamines as directing agent is taught in U.S. Pat. No. 4,108,881, the entire disclosure of which is incorporated herein by reference.
U.S. Pat. No. 4,296,083 claims synthesizing zeolites characterized by a Constraint Index of 1 to 12 and an alumina/silica mole ratio of not greater than 0.083 from a specified reaction mixture containing an organic nitrogen-containing cation, depending upon the particular zeolite desired, provided by, for example, an amine identified as being selected from the group consisting of triethylamine, trimethylamine, tripropylamine, ethylenediamine, propanediamine, butanediamine, pentanediamine, hexanediamine, methylamine, ethylamine, propylamine, butylamine, dimethylamine, diethylamine, dipropylamine, benzylamine, aniline, pyridine, piperidine and pyrrolidine. U.S. Pat. No. 4,139,600 teaches a method for synthesis of zeolite ZSM-5 (U.S. Pat. No. 3,702,886) from a reaction mixture comprising, as a directing agent, an alkyldiamine, e.g. pentanediamine or hexanediamine.
U.S. Pat. No. 4,151,189 claims a method for synthesizing zeolites ZSM-5, ZSM-12, ZSM-35 and ZSM-38 containing an organic nitrogen cation from a specified reaction mixture containing a primary amine having 2 to 9 carbon atoms as a directing agent. Octylamine is shown in said patent to direct synthesis from a particular reaction mixture of crystalline zeolite ZSM-5.
U.S. Pat. No. 4,341,748 shows synthesis of ZSM-5 or ZSM-11 from reaction mixtures comprising, for example, ethanol, ZSM-5 or ZSM-11 seeds, ethanol and seeds, ethanol and ammonium hydroxide, and ethanol, ammonium hydroxide and seeds. U.S. Pat. No. 4,100,262 teaches synthesis of ZSM-5 from a reaction mixture comprising a tetraalkylammonium source and a tetraureacobalt (II) complex.
U.S. Pat. No. 4,526,879 shows synthesis of ZSM-5 from a reaction mixture comprising a combination of a C.sub.1 -C.sub.6 primary alkylamine and a C.sub.1 -C.sub.6 alkylhalide. U.S. Pat. No. 4,495,166 teaches synthesis of ZSM-5 or ZSM-11 by replacing a portion of the conventionally used quaternary ammonium directing agent with an amine, resulting in a reaction mixture containing both an amine and a quaternary ammonium compound.
Applicant knows of no prior art for preparing crystalline silicate ZSM-11 utilizing as directing agent octylamine as required of the present invention.